Kango electric go-cart- I need help

[Whopner1@yahoo.com]

Just an update. I bought a 5k wire-wound pot with a linear taper. I held it in my hand and drove this Kango cart to see how the 5k pot would work. From a slow roll to the fastest speed I have ever seen this cart go I had very nice and continual control as I turned the pot up and down. I think the top speed was about 35, and very scary for a cart with no suspension.

I installed the pot and found that the control handle allows the pot to only rotate 45 degrees. The pot reads 106 ohms at no throttle to 1k at full throttle, which means the cart moves along at 5 mph. This is perfect for my grandkids. Goal achieved.

Now I have to find a way to set the throttle up for the advanced rider who wants to do donuts and four-wheel slides. I now see why the previous owner had installed a 20k pot with a linear taper. When the pot rotated 45 degrees, the pot did not quite reach 5k.

Maybe there is a way to install a pot that can be set at different levels for different riders of varying skill levels. I do not want to have to put in a different pot for different speed levels.

 

[Whopner1@yahoo.com]

Well, it is down to 5 mph, and the Grandkids can ride. Now I just need to set it up so that I can switch back and forth from slow to fast quickly. I am hoping I can do it with some sort of switch.

Also, I want to install reverse. Can that be done with one relay, or will I need to use two like the print shows? I read somewhere that some Golf Carts use a four-leg relay to switch the polarity to the motor.

 

[itsid]

you'd need at least six power terminals,
3+3 to be precise since the sets need to be perfectly seperated otherwise you'd short out the battery.
plus the control tabs (2) that makes a total minimum of eight
if you just take a beefy relay...

There are reversing contactors just for that but they are expensive (120 around here)
those have the two relays facing each other and the output tabs combined.
reducing the number of power tabs to indeed four
but that is NOT a common four legged relay!

it is a reversing contactor!

'sid

 

[Whopner1@yahoo.com]

I now know where the inventor for the Kango Kart lives. It would be interesting to meet them and write up the story of their original plan.

 

[Whopner1@yahoo.com]

Deep Appreciations

well, that means in case of failure that thing goes full throttle instead of shutting down...

Possible, maybe; but does that sound plausible to you?

Again easy to find out if you measure the controller (Pins 2 and 3)
volt (DC) and Amps.
Disconnect the chain before you do, since the multimeter has a bleeding resistance of something in the range of 20kOhm when measuring (at least my cheapo does).
meaning if it's like you said the motor will go full throttle while measuring (I doubt that, but I'm rather wrong than have you hurt in the process)

Now you know the max values you're dealing with.
So buying parts will be a lot easier.

'sid

[EDIT]
I checked some Curtis manuals.. and
-my apologies- you measured indeed correctly!

The Curtis control pod (PB-6) works exactly like you described.. <50 Ohms at rest 5000 Ohms at full speed.
more than 7000 or less than 40 Ohms and the controller takes that as a fault and shuts down.

So... I stand corrected... much more trouble (code wise) than the other way around, but they indeed did that back then.

Anyways..
that let's me read (again.. I read what I expect in that scaled down image)
50-5000 variable resistor
<50 = pedal at rest
5000 (+/- 100) = full throttle

and that pretty much describes the pb6 pot box for Curtis controllers.

I redraw the schematics
and used red text to make it stand out from the actual drawing a bit better
View attachment 64579

OOps I see I missed a bit.. both contactors are energized with 36V (since that's what the schematics show)
and I missed one wire color.. it was "White" If I'm seeing that correctly.
'sid

Sid, all this work you put in on my project has really helped me. Soon I will have a switch that allows the beginner to travel at 5 mph, and thrown the other way will allow the advanced rider to go "all out". Also I will have reverse limited to 5 mph with a lighted, momentary push-button on the steering wheel. You saved me dozen of hours, or more, getting this all set up.

I thank you for all the help. The experienced based competence you share really promotes go-carting.

 

[itsid]

you're very welcome;

that's what we're here for, help if and where we can.

'sid